EP 0891000 A2 19990113 - A novel method to determine the state of charge and remaining life of lithium batteries used in oilfield services applications
Title (en)
A novel method to determine the state of charge and remaining life of lithium batteries used in oilfield services applications
Title (de)
Neue Methode zur Bestimmung des Ladezustands und der restlichen Lebendauer Lithum Batterien verwendet in Ölgebietsversorgung
Title (fr)
Méthode nouvelle pour déterminer l'état de charge et la durée de vie restante de batteries au Lithium utilisées dans le secteur des forages pétroliers
Publication
Application
Priority
US 88977597 A 19970708
Abstract (en)
The present invention relates to a new method of constructing and interrogating electrochemical cells, especially those having lithium thionyl chloride (Li/SOCl2) chemistry, that permits rapid estimation of remaining discharge capacity. A preferred embodiment of the present invention employs cells with specially modified anode structures and a method for testing the state of charge and remaining life of these cells, as well as depassivating these cells, prior to their intended use or re-use. The test method can be performed using an inexpensive DC circuit and voltmeter at ambient conditions anytime prior to cell use or re-use. There is also disclosed an oilfield services downhole tool battery having a remaining life indicator comprising a housing containing one or more electrochemical cells having an internal anode means which selectively gets consumed at a predetermined state of discharge thereby creating a step change in the cell output voltage which is imperceptible to the tool while in operation at downhole temperatures, and which is capable of being detected at the surface under ambient temperatures upon administering of a suitable current load enabling the user to determine the remaining battery life at the surface prior to subsequent use or reuse of the battery in downhole oilfield services operations. <IMAGE> <IMAGE>
IPC 1-7
IPC 8 full level
H01M 6/14 (2006.01); H01M 6/50 (2006.01); H01M 4/02 (2006.01)
CPC (source: EP US)
H01M 6/14 (2013.01 - EP US); H01M 6/50 (2013.01 - EP US); H01M 6/5055 (2013.01 - EP US); H01M 2200/00 (2013.01 - EP US)
Designated contracting state (EPC)
DE FR GB IT NL
DOCDB simple family (publication)
EP 0891000 A2 19990113; EP 0891000 A3 20040630; IL 125232 A0 19990312; IL 125232 A 20010430; US 6045941 A 20000404
DOCDB simple family (application)
EP 98305373 A 19980706; IL 12523298 A 19980706; US 88977597 A 19970708